v3.25.2
Segment Information - Summary of Geographical Information (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Disclosure of geographical areas [line items]      
Sales revenues ¥ 48,036,704 ¥ 45,095,325 ¥ 37,154,298
Operating expenses 43,241,118 39,742,390 34,429,273
Operating income 4,795,586 5,352,934 2,725,025
Total assets 93,601,350 90,114,296 74,303,180
Non-current assets 17,704,029 16,486,260 14,553,580
Revenues from external customers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 48,036,704 45,095,325 37,154,298
Japan [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 21,859,094 21,020,721 17,583,196
Operating expenses 18,707,971 17,536,451 15,681,733
Operating income 3,151,123 3,484,270 1,901,463
Total assets 26,347,925 24,711,142 23,241,334
Non-current assets 6,246,879 5,827,404 5,658,859
Japan [Member] | Revenues from external customers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 10,719,120 10,193,556 9,122,282
Japan [Member] | Inter-segment revenues and transfers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 11,139,974 10,827,165 8,460,914
North America [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 19,300,327 17,943,072 13,843,901
Operating expenses 19,191,519 17,436,753 13,918,637
Operating income 108,808 506,319 (74,736)
Total assets 33,423,938 31,886,959 26,024,734
Non-current assets 7,887,494 7,374,724 6,255,561
North America [Member] | Revenues from external customers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 18,930,253 17,624,268 13,509,027
North America [Member] | Inter-segment revenues and transfers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 370,074 318,805 334,874
Europe [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 6,313,489 5,681,764 4,273,735
Operating expenses 5,897,936 5,293,668 4,216,276
Operating income 415,553 388,096 57,460
Total assets 9,463,797 8,749,680 6,813,474
Non-current assets 1,589,830 1,407,680 1,042,726
Europe [Member] | Revenues from external customers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 6,110,052 5,503,738 4,097,537
Europe [Member] | Inter-segment revenues and transfers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 203,437 178,026 176,198
Asia [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 8,988,062 8,730,749 8,044,906
Operating expenses 8,091,552 7,865,158 7,330,455
Operating income 896,510 865,591 714,451
Total assets 9,467,913 9,096,282 7,908,520
Non-current assets 1,225,158 1,190,348 1,031,057
Asia [Member] | Revenues from external customers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 7,903,360 7,604,269 7,076,922
Asia [Member] | Inter-segment revenues and transfers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 1,084,702 1,126,479 967,984
Other [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 4,521,257 4,389,785 3,472,193
Operating expenses 4,268,632 4,191,441 3,240,832
Operating income 252,626 198,345 231,362
Total assets 6,010,880 6,167,902 4,726,373
Non-current assets 754,669 686,104 565,377
Other [Member] | Revenues from external customers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 4,373,919 4,169,494 3,348,530
Other [Member] | Inter-segment revenues and transfers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues 147,338 220,292 123,663
Inter-segment Elimination/Unallocated Amount [Member]      
Disclosure of geographical areas [line items]      
Sales revenues (12,945,525) (12,670,767) (10,063,633)
Operating expenses (12,916,492) (12,581,079) (9,958,659)
Operating income (29,033) (89,687) (104,974)
Total assets 8,886,897 9,502,332 5,588,745
Inter-segment Elimination/Unallocated Amount [Member] | Inter-segment revenues and transfers [Member]      
Disclosure of geographical areas [line items]      
Sales revenues ¥ (12,945,525) ¥ (12,670,767) ¥ (10,063,633)